Sunthings

Thursday, June 13, 2013

As many of you know, I didn't get to accompany the installation due to a bicycling accident which forced me to cancel my trip. Nevertheless, The Himalayan Light Foundation proceeded and completed the installations as planned. Here is the e-mail from Yadav Gurung, the project co-ordinator:

Dear Marta,

We have successfully completed the project. The day we reached Gilung it was raining heavily. In our culture when we get rain when the visitors is in our village we take it as a good sign (its our belief). Despite the rain the Laubari Mothers Groups were at the Gilung bus stop to welcome us with flowers. When the bust stopped at Gilung and we came out of the bus they greeted us and they went inside the bus to look for you and asked me about you I told them about your accident and they were sad. But I have told them that you were ready to come ( already booked the ticked ) but due to small accident you could not travel but if you come to Nepal you will certainly visit them.

The villagers were so happy with the support, they have send you a message of "THANK YOU and GET WELL SOON". The lights at the community building has helped them to conduct various activities in the community building even during the night. The Laubari community has started literacy class in the building in the evening hours for the mothers who do not know reading and writing this light has helped them to run the literacy class under the clean solar light. The timing of the class 8:00 to 10:00 PM is set so that the mothers are free from their daily household chores and can attend the class regularly.

After completing Laubari, we installed the system at Taksar. The installation went very successfully the local boys helped us in the installation. Now the community building is complete though they have other things but not the light. The light has brought the life in the community buildings.

At Laubari we have installed 60 watt Solar Panel with six solar Led lights and at Taksar we have installed 80 watt solar panel with eight solar Led lights.

Once again thank you very much for the support and we hope to see you sometimes in a years to come.

Warm Regards,Yadav

Dear Marta,

Yes that was a very good project indeed and the villagers were so happy with the lights one good thing is they have started using the light for literacy program which is really very good result of the lights you have supported. Get well soon and I am sure one day you will visit Nepal and we go that place again.

Friday, April 19, 2013

Now that I'm home healing an injury, I might as well put the time to some use and write about something that interests me: how to explain the inner workings of a solar cell in plain language. Admittedly any discussion that involves the submacroscopic world that can't be experienced directly takes a leap of faith, a willingness to believe that theories, evidence, calculations and measurements can and do lead to successful predictions that we can actually experience in the macroscopic world. Such is the world of atoms, electrons and photons and of waves and particles. It is also a fundamental part of understanding electricity and solar cells.

It's been ages since I've written about solar cells. In some of those early posts I made an attempt at explaining solar cells in posts labelled CIGS. In this post I want to focus on the mechanism of how the stuff of sunlight, photons, interacts with the stuff of electricity, electrons. The simplest example is actually quite straightfoward: one photon gets absorbed by one electron. The photon then ceases to exist (see above regarding leap of faith) and the electron picks up all its energy. If this electron was originally trapped by an atom and if absorbing a photon gives it enough energy to break free of the atom then you have what is called the photoelectric effect.The photon itself can be of higher or lower energy, blue light being the more energetic variety and red light the less.

An electron absorbing a photon lies at the very heart of a solar cell. Remember, the end goal is for the solar cell to set electrons in motion around some external circuit and get them to do some work, like turn on a light bulb. Interesting, in a light bulb electrons can create a photons where none existed (go back to the leap of faith bit) and send them out to be enjoyed by you and me. But now I'm digressing. The slow and tired electron can then make its way back to the solar cell to see if it can get another chance at capturing a new photon.

I've only mentioned the first step in the proper functioning of a solar cell, that is, the absorption of sunlight by bound electrons enabling them to become free.

Diagram from APlusPhysics

By no means does this guarantee that they'll do any useful work. There's still the bit about setting the electrons in motion to be explained and the story of their journey is filled with pifalls and traps, walls and barriers.

Thursday, April 18, 2013

The solar panels are on their way to Gilung, Nepal and soon they will be installed. The Himalayan Light Foundation will see to the installation. But I won't be going there myself now, not at this time anyway. I managed to get caught between a car and a curb while bicycling and chose to fall onto the curb. Result, a fracure in the upper arm and a torn ligament. Doctors said not a chance to head off to Nepal next week. For the first time I can remember, I'm considering the idea of giving up bicycling and finally getting a car.

Wednesday, March 20, 2013

The project is launched! The community centers in remote Gilung in Nepal have no electricity or lights, just like much of rural Nepal. This project will bring solar lights to the two community buildings.Here is a picture of the inside of the community center.

Here is a picture of the committee members in front of the community center.

I've been trying to get the site launched for my friends who have expressly said they would like to contribute to the project, although I'd like the page to mainly serve as a gateway for information about the trip because it's set up quite well. So I hope you'll have a look just to see the specifics of the project!Update 11.8.2013: the project is complete and the link is no longer active. I've removed the link.